Draft device.



O. JONSSON.

7 DRAFT DEVICE.

APPLICATION FILED JULY 3, I915.

L L3 3 Patented June 26, 1917.

OLAF JONSSON, 0F MILWAUKEE, WISCONSIN.

DRAFT nnvrcn.

Specification of Letters Patent.

Patented June 26, 191i *3.

Application filed July 3, 1915. Serial No. 37,851.

To all whom it may concern:

Be it known that I, OLAF JoNssoN, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented certain new and useful Improvements in DraftDevices; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

The invention relates to improvements in furnaces.

The object of the present invention is to improve the construction offurnaces and to provide a suction draft of simple and comparativelyinexpensive construction designed to be applied to a battery of furnacesand adapted to create a suction or partial vacuum in the smoke pipes ofthe furnaces for drawing off the smoke and unconsumed products ofcombustion simultaneously increasing the draft of the furnaces andadapted also to return such smoke and unconsumed products of combustionto the furnaces and force the same through the fire boxes to increasethe draft and at the same time burn the said unconsumed prod nets ofcombustion whereby a more complete combustion of fuel is obtained andthe amount of smoke decreased.

With these and other objects in view the invention consists in theconstruction and novel combination and arrangement of parts hereinafterfully described, illustrated in the accompanying drawing and pointed outin the claim hereto appended, it being understood that various changes"in the form, proportion and minor details of construc tion may beresorted to without departing from the spirit or sacrificing any of theadvantages of the invention.

In the drawing Figure 1 is an elevation partly in section of a batteryof furnaces provided with a suction draft and constructed in accordancewith this invention,

Fig. 2 is a detail sectional view taken substantially on the line 2-2 ofFig. 1.

Like numerals of reference designate corresponding parts in the severalfigures of the drawing.

In the accompanying drawing in which is illustrated the preferredembodiment of the invention, 11 designate furnaces arranged in pairs,the members of each pair being provided with a common smoke pipe 2 andthe smoke pipes of the pairs of furnaces being connected at intervalswith an upper horizontal duct or pipe 3 which is connected at one endwith a smoke stack 4. The smoke stack 4; which may be of any desiredeonstruetion is common to the entire battery of furnaces and thehorizontal top pipe or duct 3 is connected at a point between thefurnaces and the smoke stack with an upper section or portion 5 of aconnecting pipe which extends from the upper pipe or duct to a lowerhorizontal pipe or duct 6. The connecting pipe is composed of the saidupper section 5 and a lower section or portion 7 which communicate attheir adjacent ends with a fan easing 8 and the upper section 5 has anarm 9 which extends over and is connected to the upper or suction ductor pipe 3 at the top thereof. A suction is created in the top pipe orduct 3 both by the stack and by the fan or blower 8 which is operated bya motor 10. An electric motor 10 is illustrated in the accompanyingdrawing for operating the fan or blower but any other form of motor mayof course be employed.

The lower pipe or draft duct (3 which preferably extends beneath thegrate of the pairs of furnaces is connected at one end to the lowerportion of the lower section 7 of the connecting pipe or duct and it isprovided at intervals with dampers 11 for controlling the draft from thebottom pipe to the individual furnaces. The dampers 11 which arepreferably of the flat type are provided with operating rods 12 or othermeans for enabling them to be readily adjusted to control the draft tothe individual furnaces. A large amount of the smoke is consumed therebyassisting in preventing the discharge of the highly objectionable blacksmoke at the smoke stack.

The lower draft duct is located slightly above the lower end of thelower section 7 of the connecting pipe or duct which section is providedat its lower end with a door 13 for removing soot and otheraccumulation. The lower depending or projecting portion 14 forms achamber or extension for trapping the soot.

IV hat is claimed is In a device of the class described, a battery offurnaces arranged in pairs, a vertical common smoke pipe for each pairof furnaces, a horizontal pipe connecting the smoke pipes, one end ofsaid horizontal pipe belng closed, a slngle smoke stack the open end ofsaid horizontal pipe being connected to said smoke stack, a suction pipeconnected to the upper portion of said horizontal pipe intermediate thesmoke stack and the battery of furnaces, a blower having a casingcoinmunicating with said suction pipe, and a transverse blast pipeleading from said eas- 10 iug and passing through the furnaces beneaththe grates thereof and provided With openings adapted to discharge tosaid furnaces, respectively.

In testimony whereof I aflix my signature in presence of two Witnesses.

OLAF J ONSSON.

Witnesses AXnL JOHNSON, CARL LINDI-IOLM.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. C.

